Earth mover



`vFeb. 17, 1942. E. w. AUSTIN EARTH MOVER Filed N0v. l, 1957 9Sheets-Sheet l NGN INVENTOR. f//S wor/ w H05/9h' l/ ATTORNEY.

Feb. 17, 1942. -w. Aus'rlN EARTH MOVER Filed Nov. 1, 1957 9 Sheets-Sheet2 Q S S E .Nm E M YQ INVENTOR.

Km wm MS Nm wm l ATTORNEY.

E. W. AUSTIN Feb. 17, 1942.

EARTH MOVER Filed Nov. l, 1957 9 Sheets-Sheet 5 INVENTOR f//5 War/bWAM/m Num! AW r :lll I.

BY M ATTORNEY.

Feb. 17, 1942. E, W AusTlN 2,273,010

' EARTH MovER Filed No'v. 1, v195'? 9 sheets-sheet 4 ATTORNEY.

Feb. 17, 1942. E. w. AUSTIN 2,273,010

EARTH M vER Filed Nv. 1, 1957 asheets-sneef 5 INVENTOR. [//51/1/or//7 M/H05/07 -BY I ATTORNEY.

Feb. 17, 1942. Erw. AUSTIN EARTH MOVER Filed NOV. l, 1937 9 sheets-sheete' INVENTOR. f//S wor/ M /7L/5//f7 MMX/w76 m E S EN MMM ATTORNEY Feb.17, 1942. EVA/.AUSTIN f 2,273,010

EARTH MOVER Filed Nov. l, 1957 9 Sheets-Sheet '7 BY W ATTORNEY.

Feb. 17, 1942. E. w. AUSTIN EARTH MOVER '9 Sheets-Sheet 8 Filed Nov. l,1937 Patented Feb. 1.7, 1942 EARTH MOVER Ellsworth W. Austin, CedarRapids, Iowa, assignor to La Plant-Choate Manufacturing Company,Incorporated, Cedar Rapids, Iowa, a corporation of Delaware ApplicationNovember 1, 1937, serial-No. 172,094

9 Claims.

My invention relates to means intended to be utilized in gathering,conveying and discharging material such as earth, when propelled by atractor orother suitable draft implement. Devices of this generalcharacter are disclosed in my Patents Nos. 2,203,713 and 2,204,033 whichissued on June 1l, 1940.

It is 'in general an object of my invention to provide an improved earthmover.

Another object of my invention is to provide an earth mover in which amain bowl is movable with respect to the main frame in a manner lgreatly to facilitate the loading and filling of the main bowl withearth.

Another object of my invention is to provide an earth mover in whichlarge ground clearance is available when the mover is in its carryingposition.

Another object of my invention is to provide an earth mover hoving avery large earth capacity yet which is positively discharged.

Another object of my invention is to provide an earth mover in which therelationship of the main bowl with respect to the main frame is variabletransversely of the structure.

The foregoing and other objects are attained in the embodiments of theinvention illustrated in the drawings, in which- Fig. 13 is a developedcross-section the planes of which are indicated by the lines I3 l-bcd-e-f-g-b-a of Figs. 12 and 13. Fig. 14 is a diagrammatic cross-sectionof a hydraulic valve in one extreme position.

Fig. 15 is a diagrammatic cross-section of a hydraulic valve in anintermediate position.

Fig. 16 is a diagrammatic cross-section of a hydraulic valve in anotherextreme position.

Fig. 17 is a schematic piping diagram of the hydraulic circuits usedinrmy earth mover.

Fig. 18 is a side elevation showing the arrangement of the remotelyoperated hydraulic valve control.

Fig. 19 is a cross-section, similar to Fig. 3,

' showing a modified jacking arrangement for Fig. 1 is a side elevationof an earth mover constructed in accordance with my invention. Y Fig. 2is -a plan of the earth mover shown in Fig. 1, portions of the gurebeing omitted to permit of an enlarged scale.

'Fig. 3 is a cross-section the plane of which is indicated by the line3-3 of Fig. 2.

Fig. 4 is a cross-section the plane of which is indicated by the line 85 of Fig. 3.

Fig. 5 is a schematic plan of the earth .mover with the :barrier memberin one position.

Fig. 6 is a schematic figure, similarlto Fig. 5,

yet showing the earth barrier in anotherposi is indicatedvby the lineII-II of Fig. 10. Fig. l2 is a cross-section the planes of which .Y areindicated by the lines I2-I2 of Fig. 1l.

I passing-in such a fashion as to' aiford a large the earth barrier.

In its preferred form, the earth mover of my invention includes astructure adapted to be moved over the ground, preferably by a draftvehicle, and incorporates an articulated supporting frame onwhich thereis movably mounted a main earth-receiving bowl provided with an earthbarrier movable through the bowl to dis charge vthe contents thereof andprovided with a front apron movable to receive, retain and assist indischarging earth, the main bowl and its appurtenant barrier and frontapron being related to thev main frame so that they are movabletransversely ofthe main frame and so that they may be related to theearth over which they are clearance when elevated and to engage theearth at'a very small angle when in digging position. The earth-movinginstrumentalities arepreferably actuated by hydraulic mechanisms all ofwhich are preferably brought under selective remote control of theoperator of the draft vehicle. I

In the form of the invention disclosed in the drawings herein, vtheearth'mover is preferably kpropelled by any suitable draft vehicle, suchas a tractor s, to which it 1s vconnected by aurea hitch '1. The drafthitch :has a pivotal connection 8 i to a steering axle 9 at its endsIforming'journals for a pair of ground-engaging front wheels I I. Ahorizontal swivel pin connection I2 and a vertl- 'cal swivel pin I3articulate the axle 9 with a front frame portion I i included in themain frame I 5 of the structure.

As a characteristic of. the presenthinvention, the

' main frame is formed oftwo portions yIll and I6 articulated or jointedwith respect to eachother in order that the portion I6 may besubstantially moved with respect to the ground I1. vThe main furthersupported on the ground I1 by a pair of rear Wheels I8, each of which ismounted upon a spindle 2| fastened to an adiacent pair of plates 22. Theplates 22- are connected together by closure plates 23 to form abox-like rearward extension of the frame portion I 6. The lower,rearward portion of each box member is pierced to receive a verticalattaching pin 24 by which av transverse tow-bar 26 is detachably held toact partially as a lateral reinforcement and partially as a point ofattachment for a following vehicle. Suitably pierced ears 21 on thetow-bar 26 form a hitch connection, so that the tractor 6 can draw notonly the vehicle disclosed in Fig. 1 but also a different or comparabletrailing vehicle attached thereto in tandem.

Reinforcement in addition to that of the towbar is provided by a boxbeam 28 fabricated of a pair of channel irons spanning the space betweenthe box members 22 and incorporated by a pair of gussets 29. Forwardlyof the box members 22 and of the beam 28, the portion I6 of the mainframe incorporates side rails 3| and 32, made preferably of opposedchannels and extending forwardly to depending forks 33 and 34 each ofwhich is pierced by one of a pair of pivot pins 36. Engaging the pinsare levers 31 and 38 sedrame, particularly the portion I8 thereof, .is

support the main bowl 6I on the frame portion I6. Extending from apivotal connection 82 between the plates of each of the box members 22,there is an extensible link 63 including a threaded turnbuckle 64 andterminating in a pivotal -connection 65 with a pair of brackets 81 onthe main bowl 6I. Each of the pairs of brackets 61 is united to thetrailing portion of an adjacent' side plate 68 of the main bowl which islocally reinforced by a'vertical channel 69. The lower portions of theside plates 68 are joined by a bottom plate 1I, the rearward part ofwhich is reinforced by a pair of nested channels 12 spanning thedistance between the side plates 68, and the forward part of which isprovided with reinforcement 13 to receive a removable serrated cuttingedge 14. The upper, generally horizontal edges of the side plates 68 areeach stiiened by longitudinally extending, inwardly facing channels 16vwhich at their rearward terminals are joined by a spanning member 11.

By operation of the turnbuckles B4 on opposite sides of the earth moverin the same direction and in unison, the general elevation of the rearend of the main bowl 6I is altered with respect to the ground I1,remaining, however, parallel to the axis of the rear wheels I 8. If thet/urncured to the rearward and lateral extremities of a yoke 39diverging from a central column 4I which, with the yoke and levers, isincluded in the frame portion I4.

In order that the front portion I4 of the frame may be articulated orjack-knifed with respect to the rear portion 'I6 of the frame about thetransverse axis dened bythe aligned pins 36,

, gussets I.

Adapted to reciprocate within the cylinder 42 is a. plunger 52 having across-pin 53 journaled in a pair of plates 54 mounted on the centralportion of the yoke 39. When hydraulic fluid is forced into the cylinder42 the plunger 52 is forced outwardly of 'the cylinder, thus raising theaxis of the pivot pins 36 with respect to the ground I1, and in eiectrotating the frame` portion I4 about the axis of the wheels II in aclockwise direction as s'een in Fig. 1, and rotating the frame portionI6 about the axis of the wheels I8 in a counterclockwise direction asseen in Fig. 1. This partial relative rotary movement of thetwo frameportions I4 and I6. is accompanied by an approaching and' recedingmovement of the front pair of wheels, so that during verticalarticulation of the main frame the wheelbase of the structurevaries inaccordance therewith. By controlling the flow of hydraulic fluid to andfrom the cylinder 42, the operator can raise and lower the main framewith respect to the ground, can alter the wheelbase of the'vehicle, andcan-readily change the relative angle or inclination of the main frameportions I4 and I6 with respect to each other and with respect to theground I1;

buckles 64 are operated different amounts or in diierent directions,then the respective parts of the rear portion of the main bowl areeither raised or lowered and, in consequence, the main bowl is given aninclination or angle transversely of the earth mover, there beingsuilicient flexibility in the structure to admit of the describedcrosswise tipping. In other words, one side of the main bowl may beadjusted to retain a position closer to the ground than the other side.

The forward portion of the main bowl 6I lis so mounted as to takeadvantage of the link mounting of the rear portion of the bowl, so thatthe bowl can be moved with respect to the main frame not only to assumepositions in consonance with the positions of the main frame butlikewise to augment and increase the movement due to the main frame.'I'he forward portion of the main bowl is provided at each side with alink 8 I, the 4lower end of which is connected by a pivot pin 82 to aportion of the associated side plate 58 which is reinforced by a member83 extending to a corner reinforcement 84. The upper end` of the link 8|is connected by a pivot pin 85 to the associated one of the side rails3| and 82. The links 8| are not parallel with the links 58 in theparticular embodiment of my invention illustrated, so that as the links8| are oscillated about their pivotal points 85 they produce acomparable oscillation of the links '63' in such a fashion that there isa pronounced vertical component to the movement of the rear part of themain bowl, with only a slight vertical In accordance with my AinventionI preferably provide an earth-carrying main bowl 6I between the frontand rear pairs of wheels, and preferably component to the movement oftheforward portion of the bowl. In this way, asthe links 8| oscillate, therear portion of the bowl 8| is raised and lowered an appreciable amount.

In order to oscillate the links 8| underv the control of the operator. Ipreferably provide connectors 88 each of which at one end engages apivot pin 82 and at the other end is connected by a pin 81 with anextension 88 from one ofV the members 31 and 38, respectively, lso thatas the front ,portion I4 of the frame is moved about the articulationpivots 36, the extension 88 transmits a comparable movement through theconnectors 86 to the pivots 82. Thus, as the main frame is jack-knifed,or its two portions |4 and I6 are moved with respect to each other, themain bowl 6| is moved with a motion having virtually the same horizontalvcomponent with respect to the main frame 'both in the forward portionand in the rearward portion, but having a greater vertical component inthe rearward portion of the main bowl than in the forward portionthereof. The particular movement described is inherent in the particularlinkage disclosed in the drawings, but by making the links 63 and 8|members of a parallel -link system, for example, the mainbowl 6| can begiven a uniform motion throughout in response to the jack-kning motionof the main frame. Various relationships of movement are possible withthe linkage mechanism of the type shown, depending upon the location ofthe pivot points and the length and dispositions of the respectivelinks; however, the precise arrangement disclosed has proved verysuccessful in practice.

When the earth mover is drawn over the ground, and the excavating'blade14 is effective to discharge loosened 'earth into the-main bowl 6|, themain bowl eventually is nearly filled and the excavated earth tends toroll forwardly and to spill out of the main bowl'in the direction ofadvance of the vehicle. To preclude this, and also to assist inretaining and subsequently discharging excavated earth from the mainbowl 6|, I provide a front apron 9| which preferably includes a curvedplate 92 having angle reinforcements 93 and 94 thereon and having anedge reinforcement 96 for approximate contact with the cutting blade 14.The apron is stiffened on each end by a plate 91 having an arcuateContour 98 approximately fitting the arcuate contour S9 of the adjacentforward edge of a side plate 68. Supporting arms |0| and |02 extend fromjunction with the plate 92 and the side plate 91, respectively, to pivotpins |03 which are at the center of the arc of the edges 98 and 99. Thepins |03 are mounted in plates |04 extending upwardly from the sideplates 68 and stiffened by diagonal braces |06 engaging the plate |04and the spanning beam 112 Secured to each of the arms |02 is a bellcrank plate |01 joined by a pivot pin |08 to a plunger |09 vprojectingfrom an hydraulic cylinder The cylinder is mounted by a pivot connection||2 between an extension ||3 on the end of the cylinder and anupstanding portion ||4 forming part of the platev |04. Since thecylinders on each side of the earth mover are connected together foroperation in unison, when hydraulic fluid is appropriately supplied tothem the plungers |09 are forced out of the cylinders Hand, through thebell crank plates |01, rotate the arms |02 in an anti-clockwisedirection, as seen in Fig. 1, about thevpivot pins |03. 'I'his raisesthe front gate 9| and retracts the plate 96 from the cutting edge 14,allowing earth to moveffrom therein to discharge at a selected rate andat appropirate times, I preferably provide the main bowl 6| with a rearwall in the form of an earth barrier ||6 or earth abutment constitutedpreferably by a generally planar transverse plate I|1 ,having aforwardly turned lower edge H6 constituting thereinforcement for acurved plate H9', so that the transverse structure is relatively still',such stiffness being augmented by reinforcing channels |2| arranged bothvertically and horizontally across the rear face of the plate ||1. Theearth barrier is supported in position largely by a pair of rollers |22,pivotally mounted on brackets |23 projecting from the plate ||1 andoperating within the inturned reinforcing channels 16. In addition tothe'support affordedby the'rollers |22, the barrier is likewisesupported and especially is .advanced and retracted by a hydraulicmechanism. 'I'his includes a plunger -|24 the forward end of which isdetachably secured in a socket |26 by a pin |21, the socket beingconnected to the barrier ||6 by suitable mounting plates |28 joined toattaching and reinforcing channels |29.

The plunger |24 operates in a hydraulic cylinder '|3| extendingrearwardly between the wheels I0 and supported on a frame plate |32which is joined to the transverse members 12 and 11. When hydraulicfluid is admitted to the cylinder |3|, the plunger |24 is expelledtherefrom and the earth barrier ||6 4is movedforwardly within the mainbowl 6| to expel the contents thereof. The earth barrier is partiallysupported, particu larly in the fully expelled positiorrof the plunger,by the rollers |22, so that its movement is free and uncramped.

In order to prevent any transverse cocking or twisting of the earthbarrier, and to avoidv the necessity of making the attachment betweenthe socket |26 and the plunger |24 unduly rigid, I- provide means formaintaining the transverse alignment or parallelism of the earthbarrier. This means` preferably includes a pair of cables |36 and |31,especially illustrated in Figs. 5 and 6. Each of the cables |36 and |31,for example, at its forward end passes through an aperture |38 in theside plate and is connected through a v turnbuckle mechanism |39 to a-nanchorage |4| adjacent side plate 68.

on the exterior of the side plate. Each of the cables extends rearwardlyadjacent the channel 16 and, passing around the end of the plate ||1,runs over a pulley |42 suitably journaledlin ears |43 projectingfrornthe rear side of the reinforcing member |2|.

Each ofthe cables then extends transversely y The hydraulic system foreffectuat-ing the I movement of the various instrumentalities oftheearth mover under control of the operator is preferably constructed inaccordance `with the showing in Figs. l0 to 18 inclusive. The workinguid is preferably oil. a body of which is containedin a reservoir ortank |5| suiably located for replenishment from time to time through anatmospheric vent and filler cap |52.l A conduit |53 leads from the tankthrough a-check valve |54 to the inlet |56 of a positive pressure pump|51, preferably a meshinggear pump suitably drivenv byy the tractor 6.As the pump rotates, it withdraws hydraulic fluid through the conduit|53 and expels it at an elevated pressure into a conduit |58, the amountof the pressure being indicated by a gauge |59 appropriately located foreasy perusal by the operator of the tractor 5. A set or definitepressure is maintained in the discharge conduit |58 by the provision ofa relief valve l5| in a bypass conduit |52 which leads from thedischarge conduit |58 back to the tank |5|. The relief valve |5| can beset atany selected pressure, for example a pressure in the neighborhoodof 1,000 lbs. per square inch, so that, despite variations in speed ofoperation of the pump |51, or variations in demand upon the hydraulicsystem, the eiective working pressure is kept approximately at the setvalue.

In order to provide a reserve or cushion to prevent undue fluctuationsin pressure incident to relatively heavy demand by operation of thehydraulic mechanism, and in order, further, to permit the utilization ofa pump of relatively small capacity, I preferably provide a means forstoring, under relatively high pressure, a quantity of working fluid,and for that reason connect to the bypass conduit |52 one or morereservoirs |53 and |54. These are tanks able to withstand high pressureand are connected by conduits |55 and |51, respectively, to the bypasspipe. When the pressure in the system in general is below the maximumset by the valve |5|, the pump discharges either into the actuatingcylinders or into the storage tanks 53 and |54. These tanks |53 and |54are not at any time entirely filled with hydraulic fluid, but are solocated that an air cushion exists in the `upper portion thereof whichacts as a cushion or spring to. maintain the requisite pressure upon theworking iiuid. When the pressure in the system arrives at the setmaximum amount, further discharge by the pump |51 is returned to thetank |5|, while when a relatively heavy4 demand for operating fluidcomes upon the system, the tanks |58 and |54 are partially discharged toaugment the discharge capacity of the pump |51.

From the discharge conduit 58 the pressure working fluid is led to aseries of valves which are utilized for the control of the hydrauliccylinders, andin order to simplify the disclosure the` valves areillustrated diagrammatically in Figs, to 17, inclusive. Each of theactuating cylinders, such as 42, has its own controlling valve, andsince all of the valves are identical they-are described primarily inconnection with Figs. 14, 15 and 16 wherein their fundamentalcharacteristics are diagrammatically illustrated. Forexample, thepressure conduit |58 leads to an inlet port or groove |58 in a valvebody |59. This groove or port is annular and encompasses a valvecylindergenerally defined by a circular wall |1| within the body |59. Adaptedto-move axially or to reciprocate within the body |59 is a valve bobbin|12 of generally-'cylindrical configuration and having a contour to aordcommunication between different parts of the hydraulic system fordifferent positions of the valve.

For example, the valve in Fig. 14 is in such a position that pressureuid from the port |58 flows around the reduced portion |13 of the valvea portion of its length, being closed off at its end by a plug |19.Pressure fluid flowing through the passage |18 leaves through radialopenings |8| between lands |82 and |83. The fluid then flows into anannular port or groove |84 in the body |59, from which it leaves througha conduit |85, to re-enter the inlet conduit |53 for recirculation bythe pump |51. There is thus maintained a continual flow of fluid throughthe valve bobbin |15 when it is in the neutral position shown in Fig.14.

When the valve bobbin is axially translated into an actuating position,as shown in Fig. 15 for example. the pressure fluid which enters throughthe port |58 and which previously has been iiowing through the internalpassage |18 is precluded longer from flowing therethrough since theopening |8| is no longer in registry with the port |84 but rather is inregistry-with the inner cylindrical wall |1| of the body |59. With thedisplacement of the valve bobbin, the land |14 has been moved to uncoveran annular port |81 in the body |59, which receives the entire inflowfrom the conduit |58 and directs it into one end of the hydraulicchamber controlled by the valve.

The addition of fluid to one end of the chamber displaces'thadouble-acting piston therein, so thatfluid from the other end of thechamber on the other side of the piston is displaced and flows back to`the body |59 through aport |88 which is annular in configuration andwhich is uncovered by the land |15 in the displaced position of thevalve. The fluid passing through the port |88 flows along the reducedportion |88 of the bobbin |12 and enters an annular port |8| which isconnected with a discharge conduit |92' leading back to the reservoir|5|.

Fluidl which is released from the actuated cylinder Vis not returned tothe pump |51 directly, but rather is returned to the reservoir |5|. Thedischarge line |92 has therefore very low frictional characteristics, sothat discharge of fluid from an actuated cylinder takes place veryrapidly. i

A displacement of the bobbin |12 in an opposite direction from theneutral position Vis illustrated in Fig. 16 wherein the land |14,instead of being moved below the port |81, is moved to a position abovethat port. In this position, working fluid entering through the port |58and passing around the bobbinto enter the internal passage |118 throughthe opening |11 isprevented from escaping from such passage since theopening |8| is in registry with the interior-cylindrical surface of thebore 1|. munication between the inlet port |58 and the port |88 which isuncovered by the land |18, so

' that pressure uid is introduced into one end of the connectedactuating cylinder through the port |58. Discharge from the other end ofthe actuating cylinder is into the port |81 and thence around a reducedportion |93 ofthe valve bobbin to the discharge pipe |92 and back to thereservoir |5I.

By suitably displacing the valve bobbin |12 in either direction fromneutral position, the operator can control the flow of hydraulic fluidin such a manner as to cause a corresponding displacement of the pistonwithin the connected hydraulic actuating'chamber andthus produce anappropriate movement of the connected instru- Y mentality of the earthmover. There is a continuous flow through the valve unit when the valvebobbin is in neutral position, in order to maintain the lines free ofair andin quick-operating condition, and likewise there is provided anarrangement in which the discharge of fluid is relatively free for quickoperation.

However, there is com- Preferably, the arrangement of the ports is suchthat when all of the valve bobbins are in neutral position the highpressure workingfluid owing through the conduit |58 and entering intothe passage |68 of the rstvalve bobbin. as seen in Fig. 17, passesthrough-the hollow center of such bobbin, discharging from the opening|84 and, instead of going directly back to the reservoir |5I, rather oWsthrough a transfer passage |94 to enter the port |68 of the next valve.The

and discharges from its corresponding port |84 through another transferpassage |96 to the port |68 on the third valve, flowing then through itshollow center and leaving thel third valve port |84 and through thereturn line |86 to the pump |51. As soon, however, as one of the bobbinsis displaced, this serial circulatory flow is interrupted and theoperation of each individual valve is as described in connection withFigs. 14 to. 16. inclusive.

While this general arrangement is readilyA applicable to the operationof any number ofcylinders to be actuated, in its present installationthere are three major instrumentalities to be f moved, one of which isprovided with a pair of cylinders, hence three valves are utilized,grouped' unit includes a casing |98 mounted on a suitable part of thetractor 6 and having a. cable |99 extending-to a suitable anchorage onthe valve casing |69 which is mounted on the forward portion I4 of themain frame of the drawn vehicle. The exible cable/|99 forms a supportand anchorage for a plurality of iiexible control shafts, collectivelydesignated 20| each of which extends from an appropriate connectioninfthe housing |98 to a gear with which meshes a'larger gear operated bya handle 202. This general subject-matter is disclosed in. my Patent2,204,033.

The exible shafts 20| are held to the cable |99 by appropriatesupporting clips 203, and each of them terminates in a fitting 204fastened to the housing |69. .Since the three controlling valves are allalike, a description of one will suffice. Any number of valves can beprovided, de-

pending upon the number of instrumentalities toA be controlled.v Theiiexible shaft 20| extends to a rotatable screw ,206 which revolveswithin an anti-friction bearing 201, held in place against axialmovement in the housing |69 by the fitting 204. The fitting 204 can beremoved for re` moval of the screw and disconnection of the shaft 20|therefrom. The threaded portion 208 of the ating inmating splines 2|3within the body 4|89 to preclude any rotation of the nut or valverboboilows through the hollow center of such valve y Yleft in Fig. 10 thethrust washer 2|1 is likewise moved to the left andcompresses the spring2|9.

Thus the bobbin is yieldingly urged into its neu` tral or medianposition. At the same time the cup leather 2|6 is effective to sealagainst oil leakage, although whateverA leakage doesvtake place past thecup leather is useful in lubricating the screw 208. Screw passages 222permit equalizing oil and air flow. i

Within the body |69, especially as shown in Fig. l1, the working fluidpressure conduit |58 is connected to the inlet passage |68 which is apassage extending to all three of the valve cylinders located in thebody |69, andterminates in a port-entirely surrounding each of the valvecylinders |1|. lrrthe neutral position of the valve shown in Fig. 11,the fluid which flows into the port |58 surrounding the valve passesinto interior channel |18 through ports |11, discharges through ports|8| into the annular port |84 which is in communication with andsubstantially surrounds its respective one of the valve bodies, and inturn merges withthe inlet port |88 of lthe next valve and so on,finally. communicating with the duct |86 through which the fluid returnsto the inlet of the pump. When the valve bobbin is displaced to theleft, for example from the position shown in Fig. 11, so that the port|81 leading to one end of the cylinder mechanism is uncovered, then thereturn flow from such cylinder courses over the end of the bobbin andout through the pierced cup 22| into a central charnber 226 whichcommunicates with all three of the valve mechanisms and likewisecommunicates bin but to permit free axial movement thereof. i

Thus, as' the shaft 20| and the screw 208 vare rotated, ,a correspondingaxial translation is imor central position, andoil leakage is largelyprecluded, by a double-acting spring-Dressed packing, generallydesignated 2|4, which includes a cup leather 2|8 in engagement withtheinterior bore of the'housing |69 and urged against a housing by acoil spring 2|9. The other end of Athrust washer 2|1- abutting a ledge2|8 in the 'a conduit 23| extending end' of the hydraulic chamber 42,for example,v

with a central passage 221-extending through the casing |89. v

At its opposite lend the passage 221 opens into a chamber 228 formed bya closure .cap 229 seated upon the casing and likewise communicatingwith the otherwise open end of each of the three valve bobbin bores, toreturn any leakageand to equalize the pressure on the bobbin ends. Thecentral passage 221 communicates with the port |9| of each of the threevalve cylinders, so that they all finally l'ead tothe conduit |92extending back to the iiuid reservoir. Thus, when .the bobbin isdisplaced to the left in Fig. 1l', flow is from one of the hydraulicchambers through the port |81, around through the pierced cup 22|,thence through the chamber 226 into the central passage 221, from whichflow takes place through and around the port 19| into the conduit |92.

During this time the pressure fluid from the conduit |58 and the port|88 is flowing around the reduced portion |13 of the bobbinand thenceflows into 4the port |88 (see Fig. 15) and into -a suitable conduit tothe other end of the respective hydraulic chamber.

As disclosed diagrammatically in Fig. i7, for example, the left-handValve |14'is connected by from the port |81 to one thecoil spring abutsa circumferentially flangedl while a conduit 232 extends from the otherend of the chamber 42 to the port |88.l Comparably, a conduit 233extends from the port |81 of the middle valve |14 to one end of each ofthe pair of chambers while the branch conduit 234' extends from theother end of each of said pair of chambers |||'to the port |88 of themiddle valve |14. In the same fashion, the conduit 236 extends from theport |81 of the right-hand valve |14 of Fig. 17, to one end of thechamber |3I, while the conduit 231 extends from the other end of suchchamber |3| to the port |88 of the righthand valve |14.

f The hydraulic arrangement is therefore such that it is remotelycontrolled by the operator of the tractor 6 in such a fashion that eachvalve is suitably actuated by the operator to provide a correspondingmovement of the hydraulic chamber which actuates the earth-movingmechanism and so that the high-pressure working fluid is maintainedrelatively free of air or gas and in rapid circulation to produce thedesired quick actuation of the moved unit.

The hydraulic arrangement may also be modied so that otherinstrumentalities than the front apron are movable by more than onejack, as shown in Fig. 19. It is an advantage to move the earth barrierquickly, but it is necessary to have a very large thrust initiallyavailable to start a full load of material out of the main bowl. 'I'heserequirements are well met by mounting on the frame plate |32 a hydrauliccylinder 24| which has the same stroke as, but a lesser diameter than,the cylinder |3|. A plunger 242 operates in the cylinder 24| and isconnected to the socket |26. For a given rate of ow of hydraulic uid,the plunger 242 reciprocates the barrier ||6 considerably faster thandoes the plunger |24, but for a given pressure of hydraulic fluid iscapable of exerting less total thrust. I have found thatthe total thrustnecessary to move a load out of the main bowl afterA it has been oncestarted is considerably less than that needed to move the loadinitially, and hence choose the diameter of the cylinder 24| and thepressure oi' the hydraulic fluid so that the force available is adequateto 4move the load after it has been .started but is insufficient tostart the load.

In order to supplement the plunger 242, I provide a4 plunger 243operating in a cylinder 244.

cross-section and welded to the adjacent members. Anadjustable terminal248 on the plunger is adapted to contact an abutment 249 'which is rwelded to the mounting -plate |28 and a channel |29 included in theearth barrier.

The cylinder 244 is hydraulically connected in.

parallel with the cylinder 24| so that when the barrier is in theposition shown in full lines in Fig 19, both plungers 242 and 243 areeiective to move the barrier initially with great power althoughrelatively slowly. As soon as the barrier arrives in the position Ashown in dotted lines in Fig. 19, the plunger-243 has reached the end ofits travel and is no longer effective, but the barrier continues for theremainder of its travel into the position B under the urgency ofthe-plunger 242, which moves at a faster rate as soon as the supply ofhydraulic liquid to cylinder 244 ceases.

. When the hydraulic flow is reversed, the parts re-- turn to theirretracted positions.

the sundry positions into which the structure can be placed by theoperator at will, as particularly illustrated in Figs. 1, 7, 8 and 9. InFig. '1, for example, the structure is actuated so that the main frameis jack-knifed downwardly to a great extent and the front apron israised, so that the main bowl is disposed for the most part below thegeneral surface of the ground with the cutting edge taking a large cutin the terrain. The cut earth is loaded into the main bowl and againstthe retracted earth barrier or rear gate. When the structure has beenoperated in this fashion for some time, partially to fill the bowl, thefront apron is dropped to aposition slightly spaced from the cuttingedge in order to catch the forward spill or roll of the additionallyexcavated earth. `When a capacity load has been introduced into the mainbowl, the front apron is closed completely and the main frame issubstantially leveled, as shown in Fig. l, so that the structure is incondition to carry a capacity load of excavated material. The positionshown in Fig. 1 is adequate where the material to be carried is Ytransported over a relatively even surface; but in the event the goingis rough and undulatory, the frame can be jack-knifed'upwardly intosubstantially the p osition shown in Fig. 8 to afford a very largeclearance, not only of the main portion of the bowl but alsoof .the rearpart thereof. When the load is to be discharged, the front apron islifted and the rear barrier is moved forwardly to expel the load, withthe main frame preferably in the position shown in Fig. 9, after whichthe structure is returned to its original position for furtherexcavation.

I claim;

1. An earth mover comprising a main frame having a forward portion and arearward portion The general utility of the earth mover depivotedtogether, ground-engaging means for directlysupporting said main frame,a main bowl, links of'variable length for supporting one end of saidmain bowl von said rearward portion, links for supporting the other endof said main bowl on said main frame, and means for moving said frameportions with respect to each other and with respect to said main bowl.

2. An earth mover comprising. a main frame including a front frameportion, a rear frame portion, and means for pivoting said portionstogether on a transverse axis, wheels directly supporting said frontframe member, wheels directly supporting said rear frame member, a mainvbowl, links pivoted to said main frame and to said main bowl forsupporting one end of said main bowl on said main frame, links pivotedto said main frame and to said main bowl for supporting the other end ofsaid main bowl on said main frame, and means for moving said main bowlwith respect to said main frame in accordance with the movement of saidpivoted portions.

3. An earth mover comprising a forward ground-engaging means, a forwardmain frame 'portion mounted to pivot on said forward tion, a main bowl,links depending from said rearward main frame portion, and means -formoving said main bowl on said links in accordance with relative pivotalmovement of said portions.

4. An earthmover comprising a frame groundtween its ends to pivot abouta transverse axis.'

means for holding said frame in any selected articulated position, anearth-carrying means,

links pivoted to said frame and to said earthcan'ying -means forsuspending said earth-carrying means from said frame, and meansresponsive to pivoting of said frame about said axis for moving saidearth-carrying means on said links 5. An earth mover comprising aforward frame portion, a rearward frame portion, ground-engaging meansfor directly supporting each of said' frame portions, means forconnecting said frame portions together for relative pivotal movement ona transverse horizontal axis, means for relatively moving said frameportions about said axis, a mainbowl, links pivoted to said bowladjacent one end' thereof and to.' one of said frame portions, linkspivoted to said bowl adjacent the other end thereof and to said one ofsaid vframe portions, and links pivoted to said bowl adjacent said otherend thereof and to the other of said frame portions.

6. An earth mover comprising a main frame ward frame portion,ground-engaging-means for directly supporting each of said frameportions,

an articulated connection between said frame portion, a rearward frameportion pivotally articulated therewith, ground-engaging meansfordirectly supporting each of said portions, a

main bowl, rigid bars each pivoted at its one end to said main bowl andat its other endto said rearward frame portion for supporting one end ofsaid bowl on said rearward frame portion, and means for supporting theother end of said bowl to move in accordance with the relative movementbetween said portions.A

8. An earth mover comprising a main frame having a forward portion and arearward portion'pivotally articulated with respect to each other,ground-engaging means directly supporting both of said portions of saidmain frame, means for moving said'forward portion and .said rearwardportion with respectto each other, a

v main bowl, rigid bars each pivoted at `its one 25 including a forwardframe portion and a rear- 1 end to said main bowl and at its other endto said rearward portion for constraining said main bowl to movement ona plurality of axes relative to said portion, and -means for moving saidmain bowl on said rearward portion in accordance with relative movementbetween said forward portion and said rearward portion.

9. An earth mover comprising a frame havingl pivotally articulated'portionseach directly supported by ground-engaging means, a main bowl,rigid bars leach pivoted at its one end to said main bowl and at itsother end to one of said portions for constraining said main .bowl tomovement on a pluralityof. axes relative to said portion, and means formoving said bowl on said portion in accordance with the relativemovement between said portions.

ELLSWOR'I'H W. AUSTIN.

` 7. A-n earth mover comprising a forward frame v

